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排序方式: 共有392条查询结果,搜索用时 15 毫秒
31.
C M Otto W J Dodds C E Greene 《Journal of the American Veterinary Medical Association》1991,198(1):129-131
Factor XII deficiency and impaired prekallikrein activity were diagnosed in a 1-year-old Chinese Shar Pei. The dog experienced repeated episodes of intestinal hemorrhage and diarrhea. Laboratory findings were compatible with blood loss (iron deficiency anemia and hypoproteinemia). Necropsy findings suggested mild infiltrative bowel disease that could have been responsible for the dog's diarrhea, but no explanation for the severe recurrent gastrointestinal hemorrhage could be found. Factor XII deficiency is uncommon in the dog and is not associated with hemorrhagic tendencies. The factor XII deficiency in this case may have contributed to the gastrointestinal hemorrhage. 相似文献
32.
Intestinal malabsorption and cryptosporidiosis in an adult dog 总被引:2,自引:0,他引:2
C E Greene G J Jacobs D Prickett 《Journal of the American Veterinary Medical Association》1990,197(3):365-367
Chronic intestinal cryptosporidiosis was diagnosed as the cause of chronic diarrhea and weight loss in an adult dog without obvious signs of immunosuppression. Results of tests for digestive function suggested that the dog had impaired intestinal absorption or bacterial overgrowth. The nutrient malabsorption might have resulted in or have been caused by the cryptosporidiosis. Temporary clinical improvement without reduction in fecal oocyst concentration was noticed following treatment with clindamycin. The dog was euthanatized. At necropsy, the dog was found to have chronic lymphoplasmacytic enteritis and cryptosporidiosis. A veterinary student that worked in the ward where the dog was kept developed cryptosporidal diarrhea. 相似文献
33.
T Krishnamurthy E W Sarver S L Greene B B Jarvis 《Journal of the Association of Official Analytical Chemists》1987,70(1):132-140
A general, sensitive gas chromatographic/negative ion chemical ionization mass spectrometric (GC/NICIMS) method of analysis was developed for the detection and quantitation of several polar, thermally labile, toxic macrocyclic trichothecenes. The procedure involves the conversion of the molecules to their corresponding alcohols (verrucarols) by alkaline hydrolysis, followed by derivatization of the hydrolysate with heptafluorobutyrylimidazole and analysis by GC/MS technique under negative ion chemical ionization conditions. Nanogram (250 ng) quantities of several macrocyclic trichothecenes with different verrucarol and ester moieties were analyzed successfully with good precision by this procedure. The method was applicable for the accurate determination of at least low ppb levels of these macrocyclic trichothecenes in environmental samples, such as fungal products, fermentation broths, and plant samples. This is the first reported, well developed, sensitive, and applicable method for the detection and quantitation of these compounds in naturally occurring samples. 相似文献
34.
Some of the current directions of scientific research on electrically conducting organic solids are reviewed. Both molecular charge transfer salts and polymers are included, with emphasis on the present level of understanding of the novel solid-state properties of these materials in terms of their chemistry and structure. For the charge transfer salts the various types of metal-to-insulator phase transitions which dominate the properties of most of these materials are discussed. Also described are the superconducting and magnetic states which have been found recently. In the case of the polymers the chemistry and physics of the conduction mechanism is examined and contrasted with that of their classical inorganic counterparts. 相似文献
35.
36.
Greene K 《Science (New York, N.Y.)》2002,296(5571):1229-1230
37.
38.
Substrate stabilization: genetically controlled reciprocal relationship of two human enzymes 总被引:8,自引:0,他引:8
5-Phosphoribosyl-l-pyrophosphate, a substrate shared by adenine phosphoribosyltransferase and hypoxanthine-guanine phosphoribosyltransferase, accumulates in human erythrocytes lacking hypoxanthine-guanine phosphoribosyltransferase. 5-Phosphoribosyl-l-pyrophosphate added to purified adenine phosphoribosyltransferase stabilizes it against heat inactivation. The increased activity of adenine phosphoribosyltransferase seen in erythrocytes deficient in hypoxanthine-guanine phosphoribosyltransferase may result from substrate stabilization of this enzyme in vivo. 相似文献
39.
Comparative analyses of behavior have an underappreciated potential for revealing the role of ethoecological factors in the origins of higher taxa. Twenty-seven species (13 genera) in the advanced family Colubridae exhibited 19 patterns of coil application; one or two patterns were usually consistent within a genus. Forty-eight species (26 genera) in the primitive families Acrochordidae, Aniliidae, Boidae, and Xenopeltidae usually used a single pattern, despite differences in age, size, shape, habitat, and diet. This implies the shared retention of an action pattern used by their common ancestor no later than the early Paleocene. Constriction must have been used as a prey-killing tactic very early in the history of snakes and might have been a behavioral "key innovation" in the evolution of their unusual jaw mechanism. 相似文献
40.
The T-cell receptor beta-chain gene has a nuclease hypersensitive site in several kinds of T cells, which does not appear in B cells expressing immunoglobulins. Conversely, the kappa immunoglobulin gene shows a known hypersensitive site at its enhancer element in B cells, as expected, but this site is absent in T cells. As is the case with immunoglobulin genes, the T-cell receptor site lies within the gene, in the intron separating joining and constant region segments. These nuclease hypersensitive DNA configurations in the introns of active T-cell receptor and immunoglobulin genes may arise from control elements that share ancestry but have diverged to the extent that each normally acts only in lymphoid cells which use the proximal gene product. 相似文献